These biomarkers are intracellular leaky markers found in high concentrations (2-3% of soluble protein) in specific cell types along the nephron including proximal convoluted tubule (alpha-GST), loops of Henle (RPA-2), distal convoluted tubule (pi-GST) and collecting ducts (RPA-1). In addition to the leaky biomarkers Biotrin also offer a specific marker of basement membrane injury (urinary collagen IV) and a generalized re-growth and repair marker called Clusterin.

The Biotrin range of renal biomarkers are available for use with human/primate, rat/mouse and cell culture (in vitro) samples.

Proximal and Distal Tubular Injury (alpha-GST & Pi-GST)
These different GST isoforms have very distince locations in the nephron. In man, Alpha-GST is localized in the proximal tubule and Pi-GST in the distal. Similarly in rats Alpha-GST is localized in the proximal tubules and GST Yb1 in the distal. This unique distribution allows renal injury to be localized to the specific parts of the nephron in human or rat studies.

Collecting Duct and Loop of Henle Injury (RPA 1 and RPA-2)
RPA-1 is the first biomarker to be localized to the luminal epithelial cells of the collecting duct. RPA-2 is specific for the loop of Henle. Again these leaky urinary biomarkers can allow differentiation of acute injury to different regions of the nephron.

Glomerular Injury (Collagen IV)
Collagen IV forms the major collagenous component of the glomerular basement membrane and is released during its turnover making it an effective fibrotic marker. Increased urinary collagen IV levels are found in several renal conditions including diabetic nephropathy.

The combined value of these biomarkers in a panel format offers a new opportunity to kidney toxicity. Click here for more information on Biotrin's Acute Kidney Injury Test.